I am struck up with a program where a listbox in created in a GUI with multiselection enabled on the listbox. I have created the listbox with selectmode as 'multiple'. But the output shows only the single value selection in the listbox.

Kindly suggest me any ideas about how to enable multivalue selection for the list box.

Also I am looking for O'Reilly's Mastering Perl/Tk ebook but couldnt find it. Please help me with a link to download the ebook.